X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;ds=sidebyside;f=syslogd.c;h=6aec78b4ef8ceab59e3d3dd3a6e7ef3da2aa2795;hb=7cf9fed83f6e7bf86eb4cac324b98734739fa861;hp=8049fc5d1675777c5b599b1631808f03f21e491e;hpb=cbe31dace5fb24304694d399b9eb267fbe752516;p=oweals%2Fbusybox.git diff --git a/syslogd.c b/syslogd.c index 8049fc5d1..6aec78b4e 100644 --- a/syslogd.c +++ b/syslogd.c @@ -7,6 +7,10 @@ * * Copyright (C) 2000 by Karl M. Hegbloom * + * "circular buffer" Copyright (C) 2001 by Gennady Feldman + * + * Maintainer: Gennady Feldman as of Mar 12, 2001 + * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or @@ -40,25 +44,8 @@ #include #include -#if ! defined __GLIBC__ && ! defined __UCLIBC__ -#include -#include -typedef unsigned int socklen_t; - -#ifndef __alpha__ -# define __NR_klogctl __NR_syslog -static inline _syscall3(int, klogctl, int, type, char *, b, int, len); -#else /* __alpha__ */ -#define klogctl syslog -#endif - -#else -# include -#endif #include "busybox.h" - - /* SYSLOG_NAMES defined to pull some extra junk from syslog.h */ #define SYSLOG_NAMES #include @@ -68,7 +55,7 @@ static inline _syscall3(int, klogctl, int, type, char *, b, int, len); #define __LOG_FILE "/var/log/messages" /* Path to the unix socket */ -char lfile[BUFSIZ] = ""; +static char lfile[BUFSIZ] = ""; static char *logFilePath = __LOG_FILE; @@ -91,6 +78,186 @@ static int doRemoteLog = FALSE; static int local_logging = FALSE; #endif +/* circular buffer variables/structures */ +#ifdef BB_FEATURE_IPC_SYSLOG + +#include +#include +#include + +/* our shared key */ +static const long KEY_ID = 0x414e4547; /*"GENA"*/ + +// Semaphore operation structures +static struct shbuf_ds { + int size; // size of data written + int head; // start of message list + int tail; // end of message list + char data[1]; // data/messages +} *buf = NULL; // shared memory pointer + +static struct sembuf SMwup[1] = {{1, -1, IPC_NOWAIT}}; // set SMwup +static struct sembuf SMwdn[3] = {{0, 0}, {1, 0}, {1, +1}}; // set SMwdn + +static int shmid = -1; // ipc shared memory id +static int s_semid = -1; // ipc semaphore id +int data_size = 16000; // data size +int shm_size = 16000 + sizeof(*buf); // our buffer size +static int circular_logging = FALSE; + +/* + * sem_up - up()'s a semaphore. + */ +static inline void sem_up(int semid) +{ + if ( semop(semid, SMwup, 1) == -1 ) + perror_msg_and_die("semop[SMwup]"); +} + +/* + * sem_down - down()'s a semaphore + */ +static inline void sem_down(int semid) +{ + if ( semop(semid, SMwdn, 3) == -1 ) + perror_msg_and_die("semop[SMwdn]"); +} + + +void ipcsyslog_cleanup(void){ + printf("Exiting Syslogd!\n"); + if (shmid != -1) + shmdt(buf); + + if (shmid != -1) + shmctl(shmid, IPC_RMID, NULL); + if (s_semid != -1) + semctl(s_semid, 0, IPC_RMID, 0); +} + +void ipcsyslog_init(void){ + if (buf == NULL){ + if ((shmid = shmget(KEY_ID, shm_size, IPC_CREAT | 1023)) == -1) + perror_msg_and_die("shmget"); + + + if ((buf = shmat(shmid, NULL, 0)) == NULL) + perror_msg_and_die("shmat"); + + + buf->size=data_size; + buf->head=buf->tail=0; + + // we'll trust the OS to set initial semval to 0 (let's hope) + if ((s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023)) == -1){ + if (errno == EEXIST){ + if ((s_semid = semget(KEY_ID, 2, 0)) == -1) + perror_msg_and_die("semget"); + }else + perror_msg_and_die("semget"); + } else { + sem_up(s_semid); + } + }else{ + printf("Buffer already allocated just grab the semaphore?"); + } +} + +/* write message to buffer */ +void circ_message(const char *msg){ + int l=strlen(msg)+1; /* count the whole message w/ '\0' included */ + + sem_down(s_semid); + + /* + * Circular Buffer Algorithm: + * -------------------------- + * + * Start-off w/ empty buffer of specific size SHM_SIZ + * Start filling it up w/ messages. I use '\0' as separator to break up messages. + * This is also very handy since we can do printf on message. + * + * Once the buffer is full we need to get rid of the first message in buffer and + * insert the new message. (Note: if the message being added is >1 message then + * we will need to "remove" >1 old message from the buffer). The way this is done + * is the following: + * When we reach the end of the buffer we set a mark and start from the beginning. + * Now what about the beginning and end of the buffer? Well we have the "head" + * index/pointer which is the starting point for the messages and we have "tail" + * index/pointer which is the ending point for the messages. When we "display" the + * messages we start from the beginning and continue until we reach "tail". If we + * reach end of buffer, then we just start from the beginning (offset 0). "head" and + * "tail" are actually offsets from the beginning of the buffer. + * + * Note: This algorithm uses Linux IPC mechanism w/ shared memory and semaphores to provide + * a threasafe way of handling shared memory operations. + */ + if ( (buf->tail + l) < buf->size ){ + /* before we append the message we need to check the HEAD so that we won't + overwrite any of the message that we still need and adjust HEAD to point + to the next message! */ + if ( buf->tail < buf->head){ + if ( (buf->tail + l) >= buf->head ){ + /* we need to move the HEAD to point to the next message + * Theoretically we have enough room to add the whole message to the + * buffer, because of the first outer IF statement, so we don't have + * to worry about overflows here! + */ + int k= buf->tail + l - buf->head; /* we need to know how many bytes + we are overwriting to make + enough room */ + char *c=memchr(buf->data+buf->head + k,'\0',buf->size - (buf->head + k)); + if (c != NULL) {/* do a sanity check just in case! */ + buf->head = c - buf->data + 1; /* we need to convert pointer to + offset + skip the '\0' since + we need to point to the beginning + of the next message */ + /* Note: HEAD is only used to "retrieve" messages, it's not used + when writing messages into our buffer */ + }else{ /* show an error message to know we messed up? */ + printf("Weird! Can't find the terminator token??? \n"); + buf->head=0; + } + } + } /* in other cases no overflows have been done yet, so we don't care! */ + + /* we should be ok to append the message now */ + strncpy(buf->data + buf->tail,msg,l); /* append our message */ + buf->tail+=l; /* count full message w/ '\0' terminating char */ + }else{ + /* we need to break up the message and "circle" it around */ + char *c; + int k=buf->tail + l - buf->size; /* count # of bytes we don't fit */ + + /* We need to move HEAD! This is always the case since we are going + * to "circle" the message. + */ + c=memchr(buf->data + k ,'\0', buf->size - k); + + if (c != NULL) /* if we don't have '\0'??? weird!!! */{ + /* move head pointer*/ + buf->head=c-buf->data+1; + + /* now write the first part of the message */ + strncpy(buf->data + buf->tail, msg, l - k - 1); + + /* ALWAYS terminate end of buffer w/ '\0' */ + buf->data[buf->size-1]='\0'; + + /* now write out the rest of the string to the beginning of the buffer */ + strcpy(buf->data, &msg[l-k-1]); + + /* we need to place the TAIL at the end of the message */ + buf->tail = k + 1; + }else{ + printf("Weird! Can't find the terminator token from the beginning??? \n"); + buf->head = buf->tail = 0; /* reset buffer, since it's probably corrupted */ + } + + } + sem_up(s_semid); +} +#endif /* Note: There is also a function called "message()" in init.c */ /* Print a message to the log file. */ static void message (char *fmt, ...) __attribute__ ((format (printf, 1, 2))); @@ -104,6 +271,16 @@ static void message (char *fmt, ...) fl.l_start = 0; fl.l_len = 1; +#ifdef BB_FEATURE_IPC_SYSLOG + if ((circular_logging == TRUE) && (buf != NULL)){ + char b[1024]; + va_start (arguments, fmt); + vsprintf (b, fmt, arguments); + va_end (arguments); + circ_message(b); + + }else +#endif if ((fd = device_open (logFilePath, O_WRONLY | O_CREAT | O_NOCTTY | O_APPEND | O_NONBLOCK)) >= 0) { @@ -197,6 +374,10 @@ static void quit_signal(int sig) { logMessage(0, "System log daemon exiting."); unlink(lfile); +#ifdef BB_FEATURE_IPC_SYSLOG + ipcsyslog_cleanup(); +#endif + exit(TRUE); } @@ -211,18 +392,20 @@ static void domark(int sig) static const int BUFSIZE = 1023; static int serveConnection (int conn) { - RESERVE_BB_BUFFER(buf, BUFSIZE + 1); + RESERVE_BB_BUFFER(tmpbuf, BUFSIZE + 1); int n_read; - while ((n_read = read (conn, buf, BUFSIZE )) > 0) { + n_read = read (conn, tmpbuf, BUFSIZE ); + + if (n_read > 0) { int pri = (LOG_USER | LOG_NOTICE); char line[ BUFSIZE + 1 ]; unsigned char c; - char *p = buf, *q = line; + char *p = tmpbuf, *q = line; - buf[ n_read - 1 ] = '\0'; + tmpbuf[ n_read - 1 ] = '\0'; while (p && (c = *p) && q < &line[ sizeof (line) - 1 ]) { if (c == '<') { @@ -248,7 +431,7 @@ static int serveConnection (int conn) /* Now log it */ logMessage (pri, line); } - return (0); + return n_read; } @@ -260,7 +443,7 @@ static void init_RemoteLog (void){ int len = sizeof(remoteaddr); bzero(&remoteaddr, len); - + remotefd = socket(AF_INET, SOCK_DGRAM, 0); if (remotefd < 0) { @@ -298,8 +481,6 @@ static void doSyslogd (void) int sock_fd; fd_set fds; - RESERVE_BB_BUFFER(lfile, BUFSIZ); - /* Set up signal handlers. */ signal (SIGINT, quit_signal); signal (SIGTERM, quit_signal); @@ -335,6 +516,12 @@ static void doSyslogd (void) FD_ZERO (&fds); FD_SET (sock_fd, &fds); +#ifdef BB_FEATURE_IPC_SYSLOG + if (circular_logging == TRUE ){ + ipcsyslog_init(); + } +#endif + #ifdef BB_FEATURE_REMOTE_LOG if (doRemoteLog == TRUE){ init_RemoteLog(); @@ -362,134 +549,36 @@ static void doSyslogd (void) --n_ready; if (fd == sock_fd) { - int conn; - pid_t pid; + //printf("New Connection request.\n"); if ((conn = accept (sock_fd, (struct sockaddr *) &sunx, &addrLength)) < 0) { perror_msg_and_die ("accept error"); } - pid = fork(); - - if (pid < 0) { - perror ("syslogd: fork"); - close (conn); - continue; - } - - if (pid == 0) { - serveConnection (conn); - close (conn); - exit( TRUE); - } - close (conn); - } - } - } - } -} - -#ifdef BB_FEATURE_KLOGD - -static void klogd_signal(int sig) -{ - klogctl(7, NULL, 0); - klogctl(0, 0, 0); - logMessage(0, "Kernel log daemon exiting."); - exit(TRUE); -} - -static void doKlogd (void) __attribute__ ((noreturn)); -static void doKlogd (void) -{ - int priority = LOG_INFO; - char log_buffer[4096]; - int i, n, lastc; - char *start; - - /* Set up sig handlers */ - signal(SIGINT, klogd_signal); - signal(SIGKILL, klogd_signal); - signal(SIGTERM, klogd_signal); - signal(SIGHUP, SIG_IGN); - -#ifdef BB_FEATURE_REMOTE_LOG - if (doRemoteLog == TRUE){ - init_RemoteLog(); - } -#endif - - logMessage(0, "klogd started: " - "BusyBox v" BB_VER " (" BB_BT ")"); - - /* "Open the log. Currently a NOP." */ - klogctl(1, NULL, 0); - - while (1) { - /* Use kernel syscalls */ - memset(log_buffer, '\0', sizeof(log_buffer)); - n = klogctl(2, log_buffer, sizeof(log_buffer)); - if (n < 0) { - char message[80]; - - if (errno == EINTR) - continue; - snprintf(message, 79, "klogd: Error return from sys_sycall: " \ - "%d - %s.\n", errno, strerror(errno)); - logMessage(LOG_SYSLOG | LOG_ERR, message); - exit(1); - } - - /* klogctl buffer parsing modelled after code in dmesg.c */ - start=&log_buffer[0]; - lastc='\0'; - for (i=0; i') i++; - start = &log_buffer[i]; - } - if (log_buffer[i] == '\n') { - log_buffer[i] = '\0'; /* zero terminate this message */ - logMessage(LOG_KERN | priority, start); - start = &log_buffer[i+1]; - priority = LOG_INFO; - } - lastc = log_buffer[i]; - } - } - -} - -#endif - -static void daemon_init (char **argv, char *dz, void fn (void)) -{ - setsid(); - chdir ("/"); - strncpy(argv[0], dz, strlen(argv[0])); - fn(); - exit(0); + FD_SET(conn, &fds); + //printf("conn: %i, set_size: %i\n",conn,FD_SETSIZE); + } else { + //printf("Serving connection: %i\n",fd); + if ( serveConnection(fd) <= 0 ) { + close (fd); + FD_CLR(fd, &fds); + } + } /* fd == sock_fd */ + }/* FD_ISSET() */ + }/* for */ + } /* for main loop */ } extern int syslogd_main(int argc, char **argv) { - int opt, pid, klogd_pid; + int opt; int doFork = TRUE; -#ifdef BB_FEATURE_KLOGD - int startKlogd = TRUE; -#endif char *p; /* do normal option parsing */ - while ((opt = getopt(argc, argv, "m:nKO:R:L")) > 0) { + while ((opt = getopt(argc, argv, "m:nO:R:LC")) > 0) { switch (opt) { case 'm': MarkInterval = atoi(optarg) * 60; @@ -497,11 +586,6 @@ extern int syslogd_main(int argc, char **argv) case 'n': doFork = FALSE; break; -#ifdef BB_FEATURE_KLOGD - case 'K': - startKlogd = FALSE; - break; -#endif case 'O': logFilePath = strdup(optarg); break; @@ -511,12 +595,17 @@ extern int syslogd_main(int argc, char **argv) if ( (p = strchr(RemoteHost, ':'))){ RemotePort = atoi(p+1); *p = '\0'; - } + } doRemoteLog = TRUE; break; case 'L': local_logging = TRUE; break; +#endif +#ifdef BB_FEATURE_IPC_SYSLOG + case 'C': + circular_logging = TRUE; + break; #endif default: show_usage(); @@ -529,6 +618,7 @@ extern int syslogd_main(int argc, char **argv) local_logging = TRUE; #endif + /* Store away localhost's name before the fork */ gethostname(LocalHostName, sizeof(LocalHostName)); if ((p = strchr(LocalHostName, '.'))) { @@ -537,26 +627,11 @@ extern int syslogd_main(int argc, char **argv) umask(0); -#ifdef BB_FEATURE_KLOGD - /* Start up the klogd process */ - if (startKlogd == TRUE) { - klogd_pid = fork(); - if (klogd_pid == 0) { - daemon_init (argv, "klogd", doKlogd); - } - } -#endif - if (doFork == TRUE) { - pid = fork(); - if (pid < 0) - exit(pid); - else if (pid == 0) { - daemon_init (argv, "syslogd", doSyslogd); - } - } else { - doSyslogd(); + if (daemon(0, 1) < 0) + perror_msg_and_die("daemon"); } + doSyslogd(); return EXIT_SUCCESS; }